Early trypsin activity is part of the signal transduction system that activates transcription of the late trypsin gene in the midgut of the mosquito, Aedes aegypti

Insect Biochem Mol Biol. 1995 Feb;25(2):241-6. doi: 10.1016/0965-1748(94)00061-l.


Trypsin activity during the first hours after feeding is essential to induce late trypsin gene expression. These results are consistent with the idea that free amino acids or other products released during digestion might be the initial signal for transcriptional activation of late trypsin. Besides early trypsin, some other factor(s) have to be translated for induction of late trypsin. This is the first case in which the proteolytic activity of a digestive enzyme is part of the signal transduction system which regulates expression of a second gene. The presence of two trypsins allows the mosquito to assess the quality of the meal and adjust the levels of late trypsin for a particular meal with remarkable flexibility.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Aedes / genetics
  • Aedes / metabolism*
  • Animals
  • Blood
  • Cycloheximide / pharmacology
  • Digestion
  • Digestive System / metabolism
  • Gene Expression Regulation
  • Protein Biosynthesis / drug effects
  • Protein Biosynthesis / physiology
  • RNA, Messenger / metabolism
  • Signal Transduction
  • Transcription, Genetic / drug effects
  • Transcription, Genetic / physiology*
  • Trypsin / genetics
  • Trypsin / metabolism*
  • Trypsin Inhibitors / pharmacology


  • RNA, Messenger
  • Trypsin Inhibitors
  • Cycloheximide
  • Trypsin